Hey, I have a question about this IL28B gene and hepatitis c treatment.........

Research has shown HCV treatment response varies in people who have an inherited (genetic) factor, referred to as the (IL28B) gene. Hepatitis C Treatment And IL-28B genotypeOther host factors may influence a chance of sustained virologic response (SVR), but the favorable IL-28B genotype "CC" is the single most important pretreatment predictor of achieving SVR with peginterferon and ribavirin therapy in genotype 1 patients.

Current standard treatments for genotype 1 include direct-acting antiviral (DAA) drugs, which target specific hepatitis C virus (HCV) enzymes. These protease inhibitors include Johnson & Johnson's newly FDA approved OLYSIO (Simeprevir), Merck's Victrelis and Incivek by Vertex. The protease inhibitors are used in combination with peginterferon and ribavirin in adults with compensated liver disease, including cirrhosis, who are treatment-naïve or who have failed previous interferon therapy (pegylated or non‑pegylated) with ribavirin. But will treatment response remain associated with IL28B genotype in patients using protease inhibitors? IL28B Genotyping Protease InhibitorsTelaprevir and Boceprevir In 2012; IL28B Genotyping in the Setting of Telaprevir and Boceprevir Therapy, research suggested IL28B genotyping may be useful in both protease inhibitors if used to individualize treatment strategies, identifying patients who can be successfully treated with shorter, simpler or cheaper regimens. IL-28B Genotyping Interferon-free TreatmentThe impact on treatment outcomes associated with IL-28B genotype in the new DAA era is still under investigation, but it appears to be minimal, according to this 2013 study published in Journal of Gastroenterology and Hepatology found online at Medscape; In the INFORM-1 study, IL28B genotype did influence early viral kinetics, and patients with the CC genotype had slightly greater reduction in HCV viral load during 14 days of interferon-free treatment. In both curative studies of prior null responders treated with asunaprevir and daclatasvir, 80–90% of patients carried IL28B CT or TT genotypes, but these did not appear to impact outcomes. Several other studies have shown no significant difference in outcomes based on IL28B genotype, although the SOUND-C2 study has shown some difference in subgroup analysis results when stratified by IL28B. Overall, IL28B genotype appears to have less impact on SVR rates relative to differences observed between HCV G1a and G1b patients.A Concern: Simeprevir - Resistant Variant

The prescribing information for Olysio includes a recommendation to screen patients with HCV genotype 1a infection at baseline for the NS3 Q80K polymorphism, a common strain of the virus in the U.S. People with this this variant have a decreased response rate to simeprevir and should be considered for an alternative therapy. Read more here about simeprevir and the NS3 Q80K Polymorphism.Quest Diagnostics offers the Hepatitis C Viral RNA NS3 genotype test.

What is a gene? A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases. The Human Genome Project has estimated that humans have between 20,000 and 25,000 genes.

Every person has two copies of each gene, one inherited from each parent.

Most genes are the same in all people, but a small number of genes (less than 1 percent of the total) are slightly different between people.

Alleles are forms of the same gene with small differences in their sequence of DNA bases. These small differences contribute to each person’s unique physical features.

Genes are made up of DNA. Each chromosome contains many genes.

How is the IL28B gene related to Hepatitis C ? The IL28B gene is involved in the immune response to some virus, including hepatitis C. Variations in the IL28B gene have been linked to better treatment response among people with chronic hepatitis C virus. What is the official name of the IL28B gene? The official name of this gene is “interleukin 28B (interferon, lambda 3).”

As background, the relevant variations—known as single nucleotide polymorphisms (SNPs), or substitution of a single building block at a specific position in the DNA chain—are located on chromosome 19 near the IL28B gene. The IL28B gene encodes instructions for making interferon lambda (a.k.a. interleukin 28). Interferons produced by the body are key to the immune system's response against hepatitis C and B; interferon therapy strengthens this natural response. ,

Will Someone Tell Me What a single nucleotide polymorphisms (SNPs) Is ? Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide. For example, a SNP may replace the nucleotide cytosine (C) with the nucleotide thymine (T) in a certain stretch of DNA. .. . SNPs occur normally throughout a person’s DNA. They occur once in every 300 nucleotides on average, which means there are roughly 10 million SNPs in the human genome. Most commonly, these variations are found in the DNA between genes. They can act as biological markers, helping scientists locate genes that are associated with disease. When SNPs occur within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the gene’s function. .

Most SNPs have no effect on health or development. Some of these genetic differences, however, have proven to be very important in the study of human health. Researchers have found SNPs that may help predict an individual’s response to certain drugs, susceptibility to environmental factors such as toxins, and risk of developing particular diseases. SNPs can also be used to track the inheritance of disease genes within families. Future studies will work to identify SNPs associated with complex diseases such as heart disease, diabetes, and cancer.Source

What Are Alleles?Alleles are corresponding pairs of genes located at specific positions in the chromosomes. Together, alleles determine the genotype of their host organism..For example, the alleles for eye color are found on chromosomes 15 and 19, and depending on which alleles someone has, he or she may have blue, brown, green, gray, or hazel eyes, and sometimes a mixture of these traits is present. Source

What Are "C" and "T" Alleles ?As mentioned above a person inherits two copies of each gene; one from each parent to make up each allele. The IL28B rs12979860 SNP has two alleles or variations which are recognized as "C" and "T". . Then What Is C/C or "CC" ?In Hepatitis C patients who have the C/C pattern simply means that they have two copies of the "C" allele.

Then What Is T/T or "TT" ?The same is true in Hepatitis C Patients who have the T/T pattern or two "T" alleles .

What Does This Mean To The Heptitis C Patient?Hepatitis C patients with the "CC" alleles have a better response to HCV therapy, according to research "CC" genotype is associated with higher sustained viral response (SVR, or viral cure) rates and faster response to interferon-based treatment. As for the TT pattern or two "T" alleles they have the least response to therapy. .

What If A Person Has The C/T pattern?The C/T pattern would mean the person has one copy of each allele. These people would fall somewhere in between.

Summarize All Of This PleaseThere are three IL28B subtypes (called genotypes): CC, CT, and TT. People with the CC genotype have a stronger immune response to HCV infection than people with the CT or TT genotypes (called non-CC genotypes). This immune response makes people who have a CC genotype more likely to clear HCV without treatment (called spontaneous viral clearance), within months of becoming infected. People who have a CC genotype are also two to three times more likely to be cured by PEG-IFN and RBV, regardless of race or HIV status.

From Medscape Gastroenterology William F. Balistreri, MDData presented at Digestive Disease Week 2010 further indicated that we can predict sustained virologic response on the basis of emerging validation of the genetic variation in regulation of the immune response to HCV.[13] The specific IL28B polymorphism (C/C, which occurs in up to 33% of patients) is strongly associated with reduced expression of intrahepatic ISGs and the response rate to PegIFN and ribavirin. Genetic variation in IL28B regulates the innate immune response to HCV in the liver, priming patients for a stronger response to exogenous IFN alpha therapy.[13]Thus, at least 5 independent studies provide overwhelming genetic evidence for the role of IL-28B in the pathogenesis of HCV infection and in spontaneous and treatment-related recovery from HCV infection. Future studies will link these findings to improved, and perhaps personalized, HCV treatment and prevention worldwide.